1. Field of the Invention
The present invention relates to a plastic screw cap composed of two cap halves on a first component wherein the screw cap is captively held on this first component, and wherein the cap halves each have an internally threaded segment and an inwardly directed ring shoulder segment for making contact with a corresponding collar of the first component, which is to be screwed together with a second component, especially for screwing the valve body of a tapping valve on the externally threaded outlet connection of a plastic or metal shipping and storage tank for liquids and loose bulk material.
2. Description of the Related Art
DE 103 01 517 B3 describes a shipping and storage tank for liquids with an inner plastic tank that stands on a pallet-like frame and an outer cage. The tapping valve of the inner tank is screwed onto the outlet connection of the inner tank by means of a plastic screw cap of a generic type, which is captively mounted on the inlet connection of the valve and is welded together from two cap halves on the inlet connection. When the screw cap is made of aluminum, the two halves of the cap are riveted together on the inlet connection of the tapping valve. This type of captive mounting of a screw cap on the inlet connection of a tapping valve is complicated and time-consuming and increases manufacturing costs.